Tony Blair warned yesterday he will not be diverted from the debate over Iran's nuclear programme by Tehran's suspected involvement in a series of deadly bomb attacks on British soldiers this year.

Speaking at Downing Street 24 hours after a British official pointed a finger of blame at Tehran, Mr Blair said: "There are certain pieces of information that lead us back to Iran."

Such attacks would not prevent Britain continuing to press for Iran to abandon its alleged nuclear weapons ambitions. "There is no justification for Iran or any other country interfering in Iraq," Mr Blair said. "Neither will we be subject to any intimidation in raising the necessary and live issues to do with the nuclear weapons obligations of Iran under the Atomic Energy Agency treaty."

Britain has repeatedly raised Iran's nuclear programme with the International Atomic Energy Agency, the United Nations nuclear watchdog, and was last month instrumental in having the issue referred to the UN security council.

Mr Blair admitted it was not clear whether Iran or Hizbullah, the Lebanon-based guerrilla group sponsored by Tehran, was behind the supply of bombs.

Hamid Babei, press counsellor at the Iranian embassy in London, said there was evidence of British involvement in supporting guerrilla attacks inside southern Iran. He said that after a bomb was detonated at Ahwaz on June 12, killing seven people, 12 suspects were arrested and interrogated. "They had some links with British forces in Basra and were trained there, and came to Iran and made that explosion," Mr Babei said. Britain rejects the charges.

The Iraqi president, Jalal Talabani, yesterday played down the allegations of Iranian involvement. "The prime minister said they are not sure," he told a meeting at Chatham House during a visit to London. "They [the British government] have some evidence that the device used was made by Iranians. It doesn't mean that the Iranian government gave it to those people. It may be that the Iranian government gave it to some other organisation and they gave it to Iraqis."

British defence officials yesterday reiterated their insistence that there is no evidence linking the explosive devices to Tehran. Military sources say that investigation of the explosives carried out by military personnel have been inconclusive because the shattered remnants leave so few clues.

Instructions on how to make shaped armour-piercing explosives of the kind used by Hizbullah are openly available on the internet, they say.